When national Homeland Security personnel warned about potential homegrown terrorists, they did not exactly mean two men in Bayonne who were allegedly brewing up explosives in an apartment to toss out the window.

But the explosions in the aftermath of the bombing at the Boston Marathon and the subsequent shootout in Watertown prompted an immediate response from the Bayonne Police Department on April 20, as well as a host of other municipal, county, and federal law-enforcement agencies. They arrived at the West 33rd Street apartment building to find several clearly dangerous devices, one of which was so unstable the Jersey City Bomb Squad had to detonate it in the yard, rather than transport it to another location.

“We do not believe this was a terrorist situation,” said Bayonne Police Chief Ralph Scianni in an interview Monday.

Police went to the apartment about 2:32 p.m., responding to a report that kids were allegedly throwing bottles from the third-floor fire escape resulting in explosions in the yard below.

“When officers arrived they were directed to the apartment,” Scianni said.

Christopher Ziobro, 21, who lived there, greeted the police officers at the door. He and Ghaias Mirza, 18, of Jersey City, were allegedly researching bomb-making on YouTube and using a variety of household items to create explosive devices, some of which they allegedly threw out the window into the yard.

This was an active scene, Scianni said, to which the Bayonne Fire Department hazardous- material team responded, as well as the Jersey City Bomb Squad.

Devices found in the apartment were examined, and those deemed dangerous were disposed of.

Ziobro and Mirza were taken into custody, eventually charged with arson, possession of a weapon of mass destruction, causing risk of widespread injury, and conspiracy.

Ziobro was also changed with suspected possession of marijuana, a switchblade knife, and a pair of brass knuckles.

Both men were processed at Bayonne Police headquarters.

Bail for both men was set at $20,000. Mirza was released on bail; Ziobro was sent to the Hudson County Correctional Facility in Kearny, awaiting a hearing at the Central Judicial Procession Court on Monday. Both men will be charged as adults.

Scianni said the incident involved the FBI Joint Terrorism Task Force, the Hudson County Prosecutor’s Office, the Office of Homeland Security, the Jersey City Police, as well as the Bayonne Police and Fire departments.

Although the building is located next to a doctor’s office as well as within a block of two churches, a dentist’s office, and other medical offices, Scianni said, “At no point was the general public at risk.”

But he did say that the investigation will continue, and that materials were seized at the site, although anything that was deemed explosive was transported to another location for controlled detonation.

The two men allegedly mixed a number of household materials that, when combined, supposedly created explosive compounds, and then allegedly dropped them off the fire escape into the yard below.

“We don’t know why they did this,” Scianni said. “But it was because someone alerted us that we were able to deal with the situation.”

Scianni said another resident in the building called the police after hearing the detonations in the yard.

“We all read that if you see something, say something; in this case an area resident did hear something and said something that allowed us to respond,” Scianni said.

A concern in the county

The Bayonne incident came at a time of heightened alert after the bombings at the Boston Marathon and subsequent investigations led federal and county law enforcement to seek evidence in West New York.

“The big danger after an incident like the one in Boston is the risk of a copycat,” said Freeholder Chairman Anthony Romano, who said security for Hudson County public buildings are under review by the Freeholder Public Safety Committee.

Many of the items that were involved in the local bomb-making in Bayonne and even the Boston bombing are common items that would not raise a red flag.

“They will now,” Romano said. “But generally, law enforcement would only see a red flag if someone bought these items in quantity.”

Incidents like the one in Bayonne or even the one in Boston are difficult to prevent since they appear not to be the work of an organized group, but of individuals. Romano said one common factor in many of these situations is the fact that the actor or actors appear to come out of broken homes.

“Incidents like 9/11 sometimes cause emotionally disturbed kids to act out,” Romano said. He said the freeholders have authorized the purchase of four high-powered sniper rifles for use by the Hudson County’s Sheriff’s Department for these situations.

“We have the Lincoln Tunnel Challenge coming up this weekend, and we will be watching this carefully, although the Port Authority does provide very good security,” he said.